similar to: [PATCH 0/5] High-speed tun receive and xmit

Generally, the Host end of the virtio ring doesn't need to see where Guest is up to in consuming the ring. However, to completely understand what's going on from the outside, this information must be exposed. For example, host can reduce the number of interrupts by detecting that the guest is currently handling previous buffers. Fortunately, we have room to expand: the ring is always a

Generally, the Host end of the virtio ring doesn't need to see where Guest is up to in consuming the ring. However, to completely understand what's going on from the outside, this information must be exposed. For example, host can reduce the number of interrupts by detecting that the guest is currently handling previous buffers. Fortunately, we have room to expand: the ring is always a

Changes from v2: added padding between avail idx and flags, and changed virtio to only publish used index when callbacks are enabled. Here's a rewrite of the original patch with a new layout. I haven't tested it yet so no idea how this performs, but I think this addresses the cache bounce issue raised by Avi. Posting for early flames/comments. Generally, the Host end of the virtio ring

Changes from v2: added padding between avail idx and flags, and changed virtio to only publish used index when callbacks are enabled. Here's a rewrite of the original patch with a new layout. I haven't tested it yet so no idea how this performs, but I think this addresses the cache bounce issue raised by Avi. Posting for early flames/comments. Generally, the Host end of the virtio ring

Hi Paolo & Co, So I've been running into another bug with SeaBIOS w/ virtio-scsi + vhost-scsi-pci code.. During the last weeks debugging on the QEMU vhost memory re-mapping bug, my seabios builds have been using a smaller target ID (16) for scanning than the default hard coded value of 256 in init_virtio_scsi(). After bumping this value back to 256 recently, a bogus out_num value from

Hi Paolo & Co, So I've been running into another bug with SeaBIOS w/ virtio-scsi + vhost-scsi-pci code.. During the last weeks debugging on the QEMU vhost memory re-mapping bug, my seabios builds have been using a smaller target ID (16) for scanning than the default hard coded value of 256 in init_virtio_scsi(). After bumping this value back to 256 recently, a bogus out_num value from

Here's a rewrite of the original patch with a new layout. I haven't tested it yet so no idea how this performs, but I think this addresses the cache bounce issue raised by Avi. Posting for early flames/comments. Generally, the Host end of the virtio ring doesn't need to see where Guest is up to in consuming the ring. However, to completely understand what's going on from the

Here's a rewrite of the original patch with a new layout. I haven't tested it yet so no idea how this performs, but I think this addresses the cache bounce issue raised by Avi. Posting for early flames/comments. Generally, the Host end of the virtio ring doesn't need to see where Guest is up to in consuming the ring. However, to completely understand what's going on from the

OK, here's a large patchset that implements the virtio spec update that I sent earlier. It supercedes the PUBLISH_USED_IDX patches I sent out earlier. I know it's a lot to ask but please test, and please consider for 2.6.40 :) I see nice performance improvements: one run showed going from 12 to 18 Gbit/s host to guest with netperf, but I did not spend a lot of time testing performance,

OK, here's a large patchset that implements the virtio spec update that I sent earlier. It supercedes the PUBLISH_USED_IDX patches I sent out earlier. I know it's a lot to ask but please test, and please consider for 2.6.40 :) I see nice performance improvements: one run showed going from 12 to 18 Gbit/s host to guest with netperf, but I did not spend a lot of time testing performance,

OK, here is the large patchset that implements the virtio spec update that I sent earlier (the spec itself needs a minor update, will send that out too next week, but I think we are on the same page here already). It supercedes the PUBLISH_USED_IDX patches I sent out earlier. What will follow will be a patchset that actually includes 4 sets of patches. I note below their status. Please consider

OK, here is the large patchset that implements the virtio spec update that I sent earlier (the spec itself needs a minor update, will send that out too next week, but I think we are on the same page here already). It supercedes the PUBLISH_USED_IDX patches I sent out earlier. What will follow will be a patchset that actually includes 4 sets of patches. I note below their status. Please consider

Hello everyone, This patch set implements packed ring support in virtio driver. Some functional tests have been done with Jason's packed ring implementation in vhost: https://lkml.org/lkml/2018/7/3/33 Both of ping and netperf worked as expected. v1 -> v2: - Use READ_ONCE() to read event off_wrap and flags together (Jason); - Add comments related to ccw (Jason); RFC (v6) -> v1: -

Hello everyone, This patch set implements packed ring support in virtio driver. Some functional tests have been done with Jason's packed ring implementation in vhost: https://lkml.org/lkml/2018/7/3/33 Both of ping and netperf worked as expected. v1 -> v2: - Use READ_ONCE() to read event off_wrap and flags together (Jason); - Add comments related to ccw (Jason); RFC (v6) -> v1: -

Hello everyone, This RFC implements packed ring support in virtio driver. Some functional tests have been done with Jason's packed ring implementation in vhost (RFC v5): https://lwn.net/Articles/755862/ Both of ping and netperf worked as expected. TODO: - Refinements (for code and commit log); - More tests and bug fixes if any; - Send the formal patch set; RFC v5 -> RFC v6: - Avoid

Hello everyone, This patch set implements packed ring support in virtio driver. Some functional tests have been done with Jason's packed ring implementation in vhost: https://lkml.org/lkml/2018/7/3/33 Both of ping and netperf worked as expected. RFC (v6) -> v1: - Avoid extra virtio_wmb() in virtqueue_enable_cb_delayed_packed() when event idx is off (Jason); - Fix bufs calculation in

Hello everyone, This RFC implements a subset of packed ring which is described at https://github.com/oasis-tcs/virtio-docs/blob/master/virtio-v1.1-packed-wd08.pdf The code was tested with DPDK vhost (testpmd/vhost-PMD) implemented by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html Minor changes are needed for the vhost code, e.g. to kick the guest. It's not a complete

Rusty, Anthony, Dor, I need your brain power :-) On smp guests I have seen a problem with virtio (the version in curent Avi's git) which do not occur on single processor guests: kernel BUG at /space/kvm/drivers/virtio/virtio_ring.c:228! illegal operation: 0001 [#1] Modules linked in: ipv6 CPU: 2 Not tainted Process swapper (pid: 0, task: 000000000f83e038, ksp: 000000000f877d70) Krnl

Rusty, Anthony, Dor, I need your brain power :-) On smp guests I have seen a problem with virtio (the version in curent Avi's git) which do not occur on single processor guests: kernel BUG at /space/kvm/drivers/virtio/virtio_ring.c:228! illegal operation: 0001 [#1] Modules linked in: ipv6 CPU: 2 Not tainted Process swapper (pid: 0, task: 000000000f83e038, ksp: 000000000f877d70) Krnl

Hello everyone, This RFC implements packed ring support in virtio driver. Some simple functional tests have been done with Jason's packed ring implementation in vhost (RFC v4): https://lkml.org/lkml/2018/5/16/501 Both of ping and netperf worked as expected w/ EVENT_IDX disabled. Ping worked as expected w/ EVENT_IDX enabled, but netperf didn't (A hack has been added in the driver to